TOPIC: Audio Streaming

I would like to get information about multicast audio streaming. I read that in order to deliver content as a multicast stream, your router must be multicast-enabled, meaning that they can transmit class D ip addresses. Does that mean I need to obtain a Class D ip address for both my router and my streaming server?? Does that mean a regular public ip addresses can't be used to deliver content as a multicast stream?? Can anyone give me more details about that, thank you.